Can anybody point me to any studies, results, experiments etc on drying techniques for washed coffee? A few of our partners in E Africa have mentioned experimenting with pyramid drying on raised beds (instead of flat drying on beds) but I've yet to see any results or follow-through cupping. I'm on my way to a month at washing stations and will be keeping aside some lots (for later cupping) that we're drying pyramid, but if any y'all have other techniques or trials to suggest then I'd very much appreciate the tips.

Not sure exactly what 'pyramid' is but in several areas in Brazil I've seen drying done on raised polipropelene tarps (about a meter off the ground) that allowed air to circulate fully around. The folks seemed pretty happy with it.

In Burundi June 2010 I saw washing stations that were drying the coffee on raised beds, but instead of spreading the parchment into a smooth surface, they groomed the parchment into little mounds or perhaps "pyramids".

The reason given was that they believe/observe that the drying period is somewhat longer using this method than with a smooth surface, and that they further believe this enhances green shelf life- always a specialconcern with E African coffees.

I don't see this method gaining much popularity in many other coffee growing countries, where increased drying times and increased labor requirements would need to be offset by significant price increases. At the very least, benefits of "pyramid" drying would need to be quantified

For that matter, raised bed drying is, all other factors being equal, slower than patio drying, because the direct contact with the warm/hot patio surface is missing.

Lots of interest in raised bed- we have partcipated in some testing that had inconclusive results.

Jim Cleaves wrote:Lots of interest in raised bed- we have partcipated in some testing that had inconclusive results.

Very good point - raised bed is often mentioned as superior, but I also haven't seen any conclusive data. I think one reason for many folks' negative association with drying on the ground is much of the stuff you see along the side of the road in coffee origns, i.e. dirty coffee on a tarp, collecting road dust and rocks, chickens walking all over it, etc. Estates often have quite well advanced patio drying, but that is often overlooked in the raised vs ground debate.

If space allows I will casually experiment with some patio drying here in Burundi and see if cupping can lend any results when compared with their standard raised bed.

Sean Starke wrote: in several areas in Brazil I've seen drying done on raised polipropelene tarps (about a meter off the ground) that allowed air to circulate fully around.

Sean - are these standard poly tarps or do they have some sort of porous quality that would allow for air flow through the tarp and up into the bottom of the coffee batch? For air flow, I can't see how a standard poly tarp would be better than the wire mesh of most raised beds.

Jim Cleaves wrote:In Burundi June 2010 I saw washing stations that were drying the coffee on raised beds, but instead of spreading the parchment into a smooth surface, they groomed the parchment into little mounds or perhaps "pyramids".

. Yup, that's it. I've heard it makes for less harsh sunlight assuming the mounds are rotated and the same beans aren't always on the outside surfaces.

Pyramid is indeed what you saw in Burundi. Many times it extends the drying time by 4-5 days. Depending on weather some Burundi washing stations are saying drying time can go up to 23 days with Pyramid drying.

As for cupping I have noticed that the washing stations I have worked with are holding up significantly better since pyramid drying and the introduction of grainpro on our lots. But that is not very scientific, and has two variables.

Last year, I had the best example of Patio vs. Rasied bed....and I am now 100% on the side of raised bed. At preship on a coffee from Latin America, I could not triangulate out the patio sample vs the Raised bed sample --- same farm, same coffee, everything the same and they tasted, more or less identical to start. However, last November I cupped them again-- 7/ 8 months off harvest, and it was night and day. Patio sample had faded, Raised bed sample was still quite good. I also think it is not a coincidence that coffee from East Africa tends to hold up so much longer than coffee from Latin America. I am sure some of it is varietal altitude ect, but I think there is enough evidence to prove slower drying leads to a more stable product.